Intellitec
131 Eisenhower Lane North
Lombard, IL 60148
630 268 0010 / 1 800 251 2408
P/N 53-00778-100 Rev. 062003
www.Intellitecsve.com
Intellitec
Application Installation and Trouble Shooting Guide
Mini-Bus Multiplex System
Page 22
Trouble Shooting
The Intellitec MiniBus multiplex system does not require special equipment to trouble shoot. Most problems
can be found with a common test light, voltmeter or ohmmeter. This guide will start out with some of the
more simple causes for trouble in the multiplex system. In most cases, the cause is usually something
simple rather than complex.
VOLTAGE
One of the most frequent problems found is low voltage. This is likely to occur if the vehicle systems have
been operating without the engine running. Measure the voltage at the battery and at the power stud on
the master (00-00778-000).
Keep in mind that
with a weak battery, voltages will fall during cranking.
If ignition is off and the interior light switches are on, the interior lights will automatically turn off when the
voltage is low. This occurs to prevent further discharge of the battery, so that there is enough left to start
the vehicle. Turning the switch off and back on again will allow several minutes of light and then the lights
will shut off again. If the voltage is not low and the light switches are on, the interior lights will also turn off
20 minutes after ignition is turned off. Cycling the switch off and back on will allow another 20 minutes.
The step well light output located on the electric door module also has a low voltage detector that will turn
the step well light off. If the voltage is low the step well light output on the door module will turn off whether
the ignition is on or off. If the vehicle is fitted with a door module, the step well light can be used as an
indicator of a low voltage condition.
The most common solution to this problem is to recharge the battery or to start the engine. A wiring
problem could also be at fault. Check the connection from the battery stud on the master to + battery and
the ground connection at J2-2 on the master.
The system will not function properly below 10 volts.
Some normal occurrences that you will notice as voltage begins to fall.
1.
2.
NORMAL FUNCTION THAT LOOKS LIKE TROUBLE
Dip Switch and Jumper settings can be configured incorrectly. These are not likely to change once the vehicle
has been in service but will need to be adjusted when replacing a module. Dip switches or jumpers are located
on the switch adapters, input modules, aux output modules and door modules. If a switch adapter is set in the
“B” position, it will not operate any of the outputs located on the master and will not operate a door module set in
the “A” position. This of course would make it appear that the system was completely inoperative. The “B”
setting is only used if a second switch adapter is used with auxiliary output modules and or a second door.
In addition to the A/B settings there are dip switch settings on the switch adapter which allow the system to be
configured so that the Aux 1 and Aux 2 outputs, located on the master, turn off with ignition or with the 20 minute
timer and low volt detector.
The switch adapter also has a selection to allow a choice of whether the electric
door will operate only with ignition on or whether it will operate regardless of whether ignition is on or off. (See
the appropriate page for each module for the proper dip switch settings.)
